Things and Processes: How Related
The contingent, external relationships of things in space and time remains a datum to be explained, but the things in question are not clearly the metaphysical last word as occupants of space and time. Consider, by way of contrast to the everyday Aristotelian-Strawsonian ontology of bodies, an ontology like that of Whitehead in which events and processes are ontologically prior to things. Natural science aside, there is a good metaphysical reason for looking with some favour on this ontology. This is the problem of truthmakers for temporally specific existence statements. Take the contingently true statement:
Bismarck and Napoleon were both alive on 18 June 1815.
What makes it true that the forty-six-year old Napoleon and the six-week old Bismarck were both (contingently) alive on this day? Not the mere existence of
For further discussion of the internality of causal relations, see the chapters by Lowe, Heil, and Yates in this volume.
these two individuals, because either or both could have died earlier: Napoleon at one of his battles such as Borodino or Leipzig, Bismarck of an infantile malady in his first month. Yet both would have existed in the sense of having been something rather than nothing. The only kinds of item connected with either European statesman that could have necessitated their existence on that day were vital processes such as breathing, the heart beating, and so on, which have two important characteristics: they were of a sort naturally necessary for their bearers to be alive then; and they essentially took place when and where they did and not at another time. These processes combined together to constitute processes sufficient to sustain a life, and occurring on that day, are truthmakers for the contingent truth above. If that is so, then the existence of a continuant such as Napoleon is dependent on there being some such processes sustaining him at some time. Not that any one of these processes is individually essential to Napoleon. Rather, he is genetically dependent on there being some such processes. Since processes other than those which did sustain him at the time might have sustained him at the time, and these might have happened elsewhere, Napoleon’s actual whereabouts on the (for him and many others) fateful day of 18 June 1815 are contingent and accidental to him.
For it to have been Napoleon who was alive at the Battle of Leipzig in 1813 and the same person who was still alive on the day of Waterloo there must have been a succession, indeed an uninterrupted and continuous succession, of sustaining vital processes. The relationships among these processes are not causal in the sense that the earlier ones cause the later, but there are myriad strands of causation running through them, like threads in a rope. Adopting Kurt Lewin’s concept of genidentity, we can say that later phases of the total sustaining process are genidentical with earlier (and vice versa). Genidentity is an equivalence relation, and the ontologically derivative invariant that is identical throughout the phases is the enduring object, Napoleon Bonaparte, for example.9
If then enduring objects are ontologically secondary to processes, this means that the ontologically prior processes have a closer tie to their spatiotemporal locations than the invariant endurants (continuants) they sustain. The processes actually sustaining Napoleon on 18 June 1815 had to be where and when they were, but there is no necessity that those actual processes had to take place: Napoleon’s genidentity train might have stopped, or have been diverted elsewhere, meaning that it was contingent where Napoleon was on that day.
-  Lewin (1922). 9 Simons (2000b).